I see it totally normal that Mudryk didn't perform very impressively this season. Because the whole squad of Chelsea were very inadequate. Their morale was so low that they even gave up on the season quite early. In this situation it wouldn't be a healthy assessment about a player. There is a new period starting for Chelsea now with Pochettino. This is going to be the most important time period to watch Mudryk's capabilities. If the team make a good start the expectation from him will also be high.
If he still can't impress people then I will also agree with the people who think he isn't good enough for Chelsea.
The transfer fee paid for Mudryk was very high. I think that's the main reason for the criticism for him. If any team pays so much for the transfer of a football player, it is naturally expected that the transferred football player will carry the team up by himself. However, Mudryk is only 22 years old and very inexperienced in the Premier league. Also, as you mentioned, Chelsea is the worst Chelsea in recent years. It's not fair to expect Mudryk to change everything on his own. Another point I agree with you is that if Mudryk performs poorly again in the new season when things are going well, then no one will stand behind him. He has to make good use of the opportunity he will get this season.